/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");

/**** 
* Classes
****/ 
// Character: the player-controlled ellipse
var Character = Container.expand(function () {
	var self = Container.call(this);
	var _char = self.attachAsset('character', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Physics
	self.velocity = 0;
	self.gravity = 2.2;
	self.flapStrength = -19;
	// Flap (jump)
	self.flap = function () {
		self.velocity = self.flapStrength;
	};
	// Update position and velocity
	self.update = function () {
		// Always apply gravity and velocity, even during powerupActive
		self.velocity += self.gravity;
		self.y += self.velocity;
	};
	// For collision detection
	self.getBounds = function () {
		return {
			x: self.x - _char.width / 2,
			y: self.y - _char.height / 2,
			width: _char.width,
			height: _char.height
		};
	};
	return self;
});
// CometParticle: a single particle for the comet trail effect
var CometParticle = Container.expand(function () {
	var self = Container.call(this);
	// Use pure white for a star-like effect
	var color = 0xffffff;
	// Use a bright ellipse as the particle
	var _shape = self.attachAsset('centerCircle', {
		anchorX: 0.5,
		anchorY: 0.5,
		scaleX: 0.22 + Math.random() * 0.18,
		scaleY: 0.16 + Math.random() * 0.14,
		color: color
	});
	// Particle properties
	self.lifetime = 22 + Math.random() * 10; // frames
	self.age = 0;
	self.vx = -6 + Math.random() * -2; // leftward
	self.vy = (Math.random() - 0.5) * 4; // slight up/down
	self.alpha = 0.85 + Math.random() * 0.15; // Brighter
	self.update = function () {
		self.x += self.vx;
		self.y += self.vy;
		self.age++;
		// Fade out, but keep a bit brighter
		self.alpha *= 0.93;
		if (self.age > self.lifetime) {
			if (self.parent) self.parent.removeChild(self);
			self.destroy();
		}
	};
	return self;
});
// Gold: collectible coin between pipes
var Gold = Container.expand(function () {
	var self = Container.call(this);
	var _gold = self.attachAsset('gold', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.collected = false;
	self._bobPhase = Math.random() * Math.PI * 2; // randomize phase so coins don't bob in sync
	self.update = function () {
		self.x += self.speed;
		// Animate gold with a gentle up-and-down bobbing motion
		self.y += Math.sin(LK.ticks / 18 + self._bobPhase) * 1.5;
	};
	// For collision detection
	self.getBounds = function () {
		return {
			x: self.x - _gold.width / 2,
			y: self.y - _gold.height / 2,
			width: _gold.width,
			height: _gold.height
		};
	};
	return self;
});
// PipePair: a pair of pipes (top and bottom) with a gap
var PipePair = Container.expand(function () {
	var self = Container.call(this);
	// Pipe dimensions
	var pipeWidth = 220;
	var pipeHeight = 1200;
	var gapHeight = 500; // Will be set dynamically
	// Top pipe
	var topPipe = self.attachAsset('pipe_top', {
		anchorX: 0,
		anchorY: 1
	});
	// Bottom pipe
	var bottomPipe = self.attachAsset('pipe_bottom', {
		anchorX: 0,
		anchorY: 0
	});
	// Set pipes' positions based on gapY and gapHeight
	self.setGap = function (gapY, gapHeight) {
		// Top pipe: bottom at gapY
		topPipe.x = 0;
		topPipe.y = gapY;
		topPipe.height = gapY;
		// Bottom pipe: top at gapY+gapHeight
		bottomPipe.x = 0;
		bottomPipe.y = gapY + gapHeight;
		bottomPipe.height = 2732 - (gapY + gapHeight);
	};
	// For collision detection
	self.getTopPipe = function () {
		return topPipe;
	};
	self.getBottomPipe = function () {
		return bottomPipe;
	};
	// Move pipes leftward
	self.update = function () {
		self.x += self.speed;
	};
	// Set initial speed
	self.speed = -12;
	return self;
});
// Powerup: special collectible (separate from Gold)
var Powerup = Container.expand(function () {
	var self = Container.call(this);
	var _powerup = self.attachAsset('powerup', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.collected = false;
	self._bobPhase = Math.random() * Math.PI * 2;
	self.update = function () {
		self.x += self.speed;
		// Animate with a gentle up-and-down bobbing motion
		self.y += Math.sin(LK.ticks / 18 + self._bobPhase) * 1.5;
	};
	self.getBounds = function () {
		return {
			x: self.x - _powerup.width / 2,
			y: self.y - _powerup.height / 2,
			width: _powerup.width,
			height: _powerup.height
		};
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x4db8ff // Light blue sky
});

/**** 
* Game Code
****/ 
// Pipes: green boxes, character: yellow ellipse, background: blue
// Game constants
// Background landscape and clouds
// unique icon for powerup
var GAME_WIDTH = 2048;
var GAME_HEIGHT = 2732;
var PIPE_WIDTH = 220;
var PIPE_GAP_MIN = 480;
var PIPE_GAP_MAX = 700;
var PIPE_DISTANCE = 900; // Horizontal distance between pipes
var PIPE_SPEED_START = -7; // Slower initial pipe speed
var PIPE_SPEED_MAX = -28;
var PIPE_FREQ_START = 120; // Pipes appear less frequently at start
var PIPE_FREQ_MIN = 45;
var GRAVITY_START = 1.05; // Slightly lower gravity for even gentler fall
var FLAP_STRENGTH = -22;
// Game variables
var pipes = [];
var golds = [];
var character;
var score = 0;
var scoreTxt;
var lastPipeTick = 0;
var pipeFreq = PIPE_FREQ_START;
var pipeSpeed = PIPE_SPEED_START;
var gameStarted = false;
var gameOver = false;
// Powerup/auto-fly state
var powerupActive = false;
var powerupPipesLeft = 0;
var autoFlyTargetY = null;
var autoFlyPipeIndex = null;
var autoFlyJustPassedPipe = false;
// Comet particle system for powerup effect
var cometParticles = [];
// Add city background image (behind landscape and clouds)
var bgCity = LK.getAsset('city', {
	anchorX: 0,
	anchorY: 1,
	x: 0,
	y: GAME_HEIGHT - 600,
	width: GAME_WIDTH,
	height: 900
});
var bgCity2 = LK.getAsset('city', {
	anchorX: 0,
	anchorY: 1,
	x: GAME_WIDTH,
	y: GAME_HEIGHT - 600,
	width: GAME_WIDTH,
	height: 900
});
game.addChild(bgCity);
game.addChild(bgCity2);
// Add background landscape (two for seamless looping)
var bgLandscape = LK.getAsset('bg_landscape', {
	anchorX: 0,
	anchorY: 1,
	x: 0,
	y: GAME_HEIGHT,
	width: GAME_WIDTH,
	height: 600
});
var bgLandscape2 = LK.getAsset('bg_landscape', {
	anchorX: 0,
	anchorY: 1,
	x: GAME_WIDTH,
	y: GAME_HEIGHT,
	width: GAME_WIDTH,
	height: 600
});
game.addChild(bgLandscape);
game.addChild(bgLandscape2);
// Add clouds (3 clouds at different positions and scales)
var clouds = [];
for (var i = 0; i < 3; i++) {
	var cloud = LK.getAsset('cloud', {
		anchorX: 0.5,
		anchorY: 0.5,
		x: 400 + i * 600,
		y: 300 + i * 120,
		scaleX: 0.8 + 0.3 * Math.random(),
		scaleY: 0.8 + 0.3 * Math.random()
	});
	game.addChild(cloud);
	clouds.push(cloud);
}
// Add score text to GUI
scoreTxt = new Text2('0', {
	size: 150,
	fill: 0xFFFFFF,
	stroke: 0x222222,
	strokeThickness: 12
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Center score text horizontally, avoid top left 100x100
scoreTxt.x = LK.gui.top.width / 2;
scoreTxt.y = 40;
// Add countdown text for auto-fly powerup
var powerupCountdownTxt = new Text2('', {
	size: 100,
	fill: 0x00ff00,
	font: "Impact, Arial Black, Tahoma"
});
powerupCountdownTxt.anchor.set(0.5, 0);
powerupCountdownTxt.x = LK.gui.top.width / 2;
powerupCountdownTxt.y = 200;
powerupCountdownTxt.visible = false;
LK.gui.top.addChild(powerupCountdownTxt);
// Add restart button to GUI (top right, not overlapping score)
var restartBtn = new Text2('⟳', {
	size: 120,
	fill: 0xffffff,
	font: "Impact, Arial Black, Tahoma"
});
restartBtn.anchor.set(1, 0); // right-top
restartBtn.x = LK.gui.top.width - 40;
restartBtn.y = 40;
restartBtn.interactive = true;
restartBtn.buttonMode = true;
restartBtn.visible = false; // Only show after pause
restartBtn.down = function (x, y, obj) {
	if (!gameOver) return;
	resetGame();
};
LK.gui.top.addChild(restartBtn);
// Show restart button after pause, hide otherwise
LK.on('pause', function () {
	restartBtn.visible = true;
});
LK.on('resume', function () {
	restartBtn.visible = false;
});
LK.on('gameover', function () {
	resetGame();
	restartBtn.visible = false;
});
// Create character and position
character = new Character();
character.x = GAME_WIDTH * 0.35;
character.y = GAME_HEIGHT / 2;
character.gravity = GRAVITY_START;
character.flapStrength = FLAP_STRENGTH;
// Add character after pipes and collectibles so it renders above them
game.addChild(character);
// Reset game state
function resetGame() {
	// Remove pipes
	for (var i = pipes.length - 1; i >= 0; i--) {
		pipes[i].destroy();
		pipes.splice(i, 1);
	}
	// Reset lastX for all pipes (defensive, in case any remain)
	for (var i = 0; i < pipes.length; i++) {
		pipes[i].lastX = undefined;
	}
	// Remove golds
	for (var i = golds.length - 1; i >= 0; i--) {
		golds[i].destroy();
		golds.splice(i, 1);
	}
	// Reset character
	character.x = GAME_WIDTH * 0.35;
	character.y = GAME_HEIGHT / 2;
	character.velocity = 0;
	character.gravity = GRAVITY_START;
	character.flapStrength = FLAP_STRENGTH;
	// Reset variables
	score = 0;
	scoreTxt.setText(score);
	lastPipeTick = 0;
	pipeFreq = PIPE_FREQ_START; // Use new slower frequency
	pipeSpeed = PIPE_SPEED_START; // Use new slower speed
	gameStarted = false;
	gameOver = false;
	// Reset powerup/auto-fly state
	powerupActive = false;
	powerupPipesLeft = 0;
	autoFlyTargetY = null;
	autoFlyPipeIndex = null;
	autoFlyJustPassedPipe = false;
	// Reset bird color and stop blinking
	if (character._powerupBlinkTween) tween.stop(character, {
		tint: true
	});
	character.tint = 0xffffff;
	character._powerupBlinking = false;
	character._powerupBlinkTween = null;
	character._powerupBlinkStep = 0;
	character._powerupBlinkTotal = 0;
	// Hide countdown text
	if (typeof powerupCountdownTxt !== "undefined") {
		powerupCountdownTxt.visible = false;
		powerupCountdownTxt.setText('');
	}
	// Clear any pending auto-fly end timeout
	if (game._powerupEndTimeout) {
		LK.clearTimeout(game._powerupEndTimeout);
		game._powerupEndTimeout = null;
	}
}
// Start game on first tap
function startGame() {
	if (!gameStarted && !gameOver) {
		gameStarted = true;
		character.flap();
	}
}
// Flap on tap/click
game.down = function (x, y, obj) {
	if (gameOver) return;
	// Allow input during powerup auto-fly
	if (!gameStarted) {
		startGame();
	} else {
		character.flap();
	}
};
// Main update loop
game.update = function () {
	if (gameOver) return;
	// Animate clouds (move right to left, loop)
	var bgMoveSpeed = Math.abs(pipeSpeed) * 0.5;
	if (powerupActive && autoFlyPipeIndex !== null && pipes[autoFlyPipeIndex]) {
		// During auto-fly, match background and clouds speed to the pipe's speed
		bgMoveSpeed = Math.abs(pipes[autoFlyPipeIndex].speed) * 0.5;
	}
	for (var i = 0; i < clouds.length; i++) {
		var cloud = clouds[i];
		var cloudMoveSpeed = 0.7 + 0.2 * i;
		if (powerupActive && autoFlyPipeIndex !== null && pipes[autoFlyPipeIndex]) {
			cloudMoveSpeed = Math.abs(pipes[autoFlyPipeIndex].speed) * (0.7 + 0.2 * i) / Math.abs(pipeSpeed);
		}
		cloud.x -= cloudMoveSpeed;
		if (cloud.x < -cloud.width / 2) {
			cloud.x = GAME_WIDTH + cloud.width / 2 + Math.random() * 200;
			cloud.y = 200 + Math.random() * 400 + i * 100;
		}
	}
	// Animate city background to move leftward and loop (slower for parallax effect)
	var cityMoveSpeed = bgMoveSpeed * 0.5;
	bgCity.x -= cityMoveSpeed;
	bgCity2.x -= cityMoveSpeed;
	if (bgCity.x <= -GAME_WIDTH) {
		bgCity.x = bgCity2.x + GAME_WIDTH;
	}
	if (bgCity2.x <= -GAME_WIDTH) {
		bgCity2.x = bgCity.x + GAME_WIDTH;
	}
	// Animate background landscape to move leftward and loop
	bgLandscape.x -= bgMoveSpeed;
	bgLandscape2.x -= bgMoveSpeed;
	// Loop both backgrounds for seamless scrolling
	if (bgLandscape.x <= -GAME_WIDTH) {
		bgLandscape.x = bgLandscape2.x + GAME_WIDTH;
	}
	if (bgLandscape2.x <= -GAME_WIDTH) {
		bgLandscape2.x = bgLandscape.x + GAME_WIDTH;
	}
	if (!gameStarted) {
		// Idle animation: bob up and down
		character.y = GAME_HEIGHT / 2 + Math.sin(LK.ticks / 30) * 30;
		return;
	}
	// Character physics
	if (powerupActive) {
		// Find the next pipe to pass if needed
		if (autoFlyPipeIndex === null || autoFlyPipeIndex >= pipes.length) {
			// Find the next pipe
			for (var pi = 0; pi < pipes.length; pi++) {
				if (!pipes[pi].passed && pipes[pi].x + PIPE_WIDTH / 2 > character.x) {
					autoFlyPipeIndex = pi;
					break;
				}
			}
			if (autoFlyPipeIndex === null && pipes.length > 0) autoFlyPipeIndex = pipes.length - 1;
		}
		// Set target Y to the center of the gap of the next pipe
		if (autoFlyPipeIndex !== null && pipes[autoFlyPipeIndex]) {
			var pipePair = pipes[autoFlyPipeIndex];
			// Calculate gap center
			var gapY = pipePair.getTopPipe().height;
			var gapHeight = pipePair.getBottomPipe().y - pipePair.getTopPipe().height;
			autoFlyTargetY = gapY + gapHeight / 2;
			// Do NOT override character.x or character.y; player keeps full control
			// Calculate the pipe's center X
			var pipeCenterX = pipePair.x + PIPE_WIDTH / 2;
			// Store the last pipe center X for transition detection
			if (pipePair.lastX === undefined) pipePair.lastX = pipeCenterX;
			// Detect passing through the pipe (only when crossing the pipe center this frame)
			if (pipePair.lastX >= character.x && pipeCenterX < character.x) {
				powerupPipesLeft--;
				autoFlyJustPassedPipe = true;
			}
			// When the pipe is behind, reset for next pipe
			if (autoFlyJustPassedPipe && pipeCenterX < character.x - 40) {
				autoFlyPipeIndex++;
				autoFlyJustPassedPipe = false;
			}
			pipePair.lastX = pipeCenterX;
			// Animate bird's color to blink green during auto-fly, increasing blink frequency towards the end
			if (!character._powerupBlinking) {
				character._powerupBlinking = true;
				character._powerupBlinkTween = null;
				character._powerupBlinkStep = 0;
				character._powerupBlinkTotal = powerupPipesLeft * 12; // estimate 12 blinks per pipe
			}
			if (character._powerupBlinking) {
				// Calculate blink frequency: faster as powerupPipesLeft decreases
				var minBlink = 180,
					maxBlink = 60; // ms
				var blinkDuration = minBlink - (minBlink - maxBlink) * (3 - powerupPipesLeft) / 3;
				if (!character._powerupBlinkTween || character._powerupBlinkTween._finished) {
					// Alternate between green and normal
					var toGreen = character._powerupBlinkStep % 2 === 0;
					var targetTint = toGreen ? 0x00ff00 : 0xffffff;
					if (character._powerupBlinkTween) tween.stop(character, {
						tint: true
					});
					character._powerupBlinkTween = tween(character, {
						tint: targetTint
					}, {
						duration: blinkDuration,
						easing: tween.linear
					});
					character._powerupBlinkStep++;
				}
			}
		}
		// Show and update countdown text during auto-fly
		if (powerupActive && powerupPipesLeft > 0) {
			powerupCountdownTxt.visible = true;
			powerupCountdownTxt.setText("You are immortal for: " + powerupPipesLeft);
		} else {
			powerupCountdownTxt.visible = false;
		}
		// End powerup after 3 pipes, but delay deactivation by 0.5s
		if (powerupPipesLeft <= 0 && powerupActive) {
			if (!game._powerupEndTimeout) {
				game._powerupEndTimeout = LK.setTimeout(function () {
					powerupActive = false;
					autoFlyTargetY = null;
					autoFlyPipeIndex = null;
					autoFlyJustPassedPipe = false;
					// Stop blinking and reset color
					if (character._powerupBlinkTween) tween.stop(character, {
						tint: true
					});
					character.tint = 0xffffff;
					character._powerupBlinking = false;
					character._powerupBlinkTween = null;
					character._powerupBlinkStep = 0;
					character._powerupBlinkTotal = 0;
					// Stop powerupmusic and fade bgmusic back to 100%
					LK.stopMusic('powerupmusic');
					LK.playMusic('bgmusic', {
						fade: {
							start: 0.2,
							end: 1,
							duration: 400
						}
					});
					game._powerupEndTimeout = null;
				}, 500);
			}
		}
		// Always call character.update() so player has full control
		character.update();
		// Spawn comet particles if powerupActive
		if (powerupActive) {
			// Spawn 2-3 particles per frame for a dense trail
			for (var cp = 0; cp < 2 + Math.floor(Math.random() * 2); cp++) {
				var p = new CometParticle();
				// Place particle slightly behind and below the bird for a comet tail
				p.x = character.x - 40 + Math.random() * 10;
				p.y = character.y + 20 + Math.random() * 16 - 8;
				p.alpha = 0.6 + Math.random() * 0.25;
				cometParticles.push(p);
				game.addChildAt ? game.addChildAt(p, 0) : game.addChild(p); // add behind bird if possible
			}
		}
		// Update and clean up comet particles
		for (var i = cometParticles.length - 1; i >= 0; i--) {
			var part = cometParticles[i];
			part.update();
			if (part.age > part.lifetime || part.alpha < 0.05) {
				if (part.parent) part.parent.removeChild(part);
				cometParticles.splice(i, 1);
			}
		}
	} else {
		character.update();
	}
	// Clamp character to screen
	if (character.y < character.attachAsset('character', {
		anchorX: 0.5,
		anchorY: 0.5
	}).height / 2) {
		character.y = character.attachAsset('character', {
			anchorX: 0.5,
			anchorY: 0.5
		}).height / 2;
		character.velocity = 0;
	}
	if (character.y > GAME_HEIGHT - character.attachAsset('character', {
		anchorX: 0.5,
		anchorY: 0.5
	}).height / 2) {
		character.y = GAME_HEIGHT - character.attachAsset('character', {
			anchorX: 0.5,
			anchorY: 0.5
		}).height / 2;
		character.velocity = 0;
		if (!powerupActive) {
			triggerGameOver();
			return;
		}
		// If powerupActive, do not trigger game over, just clamp position
	}
	// Pipes movement and collision
	for (var i = pipes.length - 1; i >= 0; i--) {
		var pipePair = pipes[i];
		pipePair.update();
		// Remove pipes off screen
		if (pipePair.x + PIPE_WIDTH < 0) {
			pipePair.destroy();
			pipes.splice(i, 1);
			continue;
		}
		// Collision detection
		var charBounds = character.getBounds();
		var topPipe = pipePair.getTopPipe();
		var bottomPipe = pipePair.getBottomPipe();
		// Top pipe collision
		if (rectsIntersect(charBounds, {
			x: pipePair.x,
			y: 0,
			width: PIPE_WIDTH,
			height: topPipe.height
		})) {
			if (!powerupActive) {
				triggerGameOver();
				return;
			}
			// If powerupActive, ignore collision and allow player to keep playing
		}
		// Bottom pipe collision
		if (rectsIntersect(charBounds, {
			x: pipePair.x,
			y: bottomPipe.y,
			width: PIPE_WIDTH,
			height: bottomPipe.height
		})) {
			if (!powerupActive) {
				triggerGameOver();
				return;
			}
			// If powerupActive, ignore collision and allow player to keep playing
		}
		// Score: when character passes the pipe (center)
		if (!pipePair.passed && pipePair.x + PIPE_WIDTH / 2 < character.x) {
			pipePair.passed = true;
			score += 1;
			scoreTxt.setText(score);
			// Increase difficulty
			if (pipeFreq > PIPE_FREQ_MIN) {
				pipeFreq -= 2;
				if (pipeFreq < PIPE_FREQ_MIN) pipeFreq = PIPE_FREQ_MIN;
			}
			if (pipeSpeed > PIPE_SPEED_MAX) {
				pipeSpeed -= 0.5;
				if (pipeSpeed < PIPE_SPEED_MAX) pipeSpeed = PIPE_SPEED_MAX;
			}
			character.gravity += 0.02;
		}
	}
	// Golds movement and collection
	for (var i = golds.length - 1; i >= 0; i--) {
		var gold = golds[i];
		gold.update();
		// Remove gold if off screen
		if (gold.x + 50 < 0) {
			gold.destroy();
			golds.splice(i, 1);
			continue;
		}
		// Collision with character
		if (!gold.collected && rectsIntersect(character.getBounds(), gold.getBounds())) {
			gold.collected = true;
			gold.destroy();
			golds.splice(i, 1);
			// Only increase score if this is a Gold, not a Powerup
			if (gold instanceof Gold) {
				LK.getSound('goldcollect').play();
				score += 3;
				scoreTxt.setText(score);
			}
			// Powerup collection: activate or extend auto-fly mode
			if (gold instanceof Powerup) {
				LK.getSound('powerupcollect').play();
				// Stop powerupmusic if already playing before starting again
				LK.stopMusic('powerupmusic');
				// Fade out bgmusic to 20% and play powerupmusic
				LK.playMusic('bgmusic', {
					fade: {
						start: 1,
						end: 0.2,
						duration: 400
					}
				});
				LK.playMusic('powerupmusic', {
					loop: false
				});
				if (!powerupActive) {
					powerupActive = true;
					powerupPipesLeft = 3;
					// Find the next pipe the player will pass
					autoFlyPipeIndex = null;
					for (var pi = 0; pi < pipes.length; pi++) {
						if (!pipes[pi].passed && pipes[pi].x + PIPE_WIDTH / 2 > character.x) {
							autoFlyPipeIndex = pi;
							break;
						}
					}
					// If not found, just use the last pipe
					if (autoFlyPipeIndex === null && pipes.length > 0) autoFlyPipeIndex = pipes.length - 1;
					autoFlyTargetY = null;
					autoFlyJustPassedPipe = false;
					// Set velocity to 0, but do NOT override y or gravity; player keeps control, collisions are ignored
					character.velocity = 0;
					// Start blinking effect
					character._powerupBlinking = false;
					character._powerupBlinkTween = null;
					character._powerupBlinkStep = 0;
					character._powerupBlinkTotal = 0;
				} else {
					// If already active, increase duration by 3 more pipes, but cap at 3
					powerupPipesLeft += 3;
					if (powerupPipesLeft > 3) powerupPipesLeft = 3;
					// Cancel pending end timeout if any, so effect doesn't end early
					if (game._powerupEndTimeout) {
						LK.clearTimeout(game._powerupEndTimeout);
						game._powerupEndTimeout = null;
					}
				}
			}
			// Optionally: add a flash or effect here
		}
	}
	// --- Ensure character is always rendered above pipes and golds ---
	if (character.parent) {
		character.parent.removeChild(character);
	}
	game.addChild(character);
	// Pipe spawning
	if (LK.ticks - lastPipeTick >= pipeFreq) {
		spawnPipePair();
		lastPipeTick = LK.ticks;
	}
};
// Rectangle intersection helper
function rectsIntersect(a, b) {
	return a.x < b.x + b.width && a.x + a.width > b.x && a.y < b.y + b.height && a.y + a.height > b.y;
}
// Spawn a new pipe pair
function spawnPipePair() {
	var gapHeight = PIPE_GAP_MIN + Math.floor(Math.random() * (PIPE_GAP_MAX - PIPE_GAP_MIN + 1));
	var minGapY = 180;
	var maxGapY = GAME_HEIGHT - gapHeight - 180;
	var gapY = minGapY + Math.floor(Math.random() * (maxGapY - minGapY + 1));
	var pipePair = new PipePair();
	pipePair.x = GAME_WIDTH;
	pipePair.y = 0;
	pipePair.setGap(gapY, gapHeight);
	pipePair.speed = pipeSpeed;
	pipePair.passed = false;
	pipes.push(pipePair);
	game.addChild(pipePair);
	// 15% chance to spawn Powerup, 85% chance to spawn Gold
	if (Math.random() < 0.15) {
		var powerup = new Powerup();
		powerup.x = pipePair.x + PIPE_WIDTH / 2 + 60;
		powerup.y = gapY + gapHeight / 2;
		powerup.speed = pipeSpeed;
		golds.push(powerup);
		game.addChild(powerup);
	} else {
		var gold = new Gold();
		gold.x = pipePair.x + PIPE_WIDTH / 2 + 60;
		gold.y = gapY + gapHeight / 2;
		gold.speed = pipeSpeed;
		golds.push(gold);
		game.addChild(gold);
	}
}
// Game over logic
function triggerGameOver() {
	if (gameOver) return;
	gameOver = true;
	LK.getSound('hitsound').play();
	LK.effects.flashScreen(0xff0000, 800);
	// Do not stop or fade out bgmusic here; let it continue during game over screen
	// (No call to LK.stopMusic or LK.playMusic for bgmusic here)
	LK.showGameOver();
}
// Reset game on game over
LK.on('gameover', function () {
	resetGame();
});
// Initial game state
resetGame();
LK.playMusic('bgmusic');